My Story: I've always been heavy, but the pounds really piled on during my four pregnancies. After my second child was born, I started exercising. The problem was that I didn't know how to push myself, so I never saw real results. I tried a few diets, but could never stick to them.

Worst Moment: In front of my middle school class in Tucson, AZ, I tripped and hit the ground but quickly pulled myself up. One of the students said, "Man, I didn't know fat people could move so fast." I was shocked by his rudeness, but mostly, I was humiliated.

Turning Point: When I visited the doctor four years ago, I got bad news: I was borderline diabetic. My mom has diabetes, so I was alarmed — I know how hard it is for her. For the first time in my life, I decided to make changes.

How I Lost It: I was addicted to sugar, so I had to wean myself off the stuff. First, I switched to diet soda and other foods with artificial sweeteners, so I could cut my calorie intake. Now I only eat natural sugars, like those found in honey or fruit. Later, while coaching the girls' soccer team after school, I discovered running. The team was whining about doing laps, so I said, "If you run four laps, I'll run one." They took me up on it. My first attempt was torture, but I was running four laps by the end of the season (with the encouragement of my 25 "cheerleaders"!). Now I log about 50 miles a week.

Favorite Tricks: I've always eaten a lot, and that hasn't changed — but now I wolf down only healthy foods, like steamed veggies. To boost my metabolism, I also started lifting weights.